1. Field of the Invention
This invention relates to a new and improved plastic bottle cap of the type used as a tamper-evident closure for large (e.g., 5-gallon) bottles for water. More particularly, the invention relates to a cap having vertical internal ribs which improve performance during capping by insuring the cap seats on the bottle neck properly and reduces frictional resistance to capping. Further, the invention relates to a cap so constructed that it will securely seal the necks of bottles of different manufacturers having somewhat different neck profiles. There are several manufacturers of such bottles and a number of these manufacturers produce bottles having profiles which differ to an extent, but are generally the same. The cap of the present invention is so constructed that it will seal plural neck profiles. A further feature of the present invention is the fact that the cap will accommodate necks which have been somewhat damaged and still provide a tight seal.
2. Description of Related Art
Heretofore, plastic caps for containers of the general type of 5-gallon water bottles have been closed with caps which accommodate different neck finishes. Thus, caps such as are shown in U.S. Pat. Nos. 3,392,860 and 3,840,137 accommodate neck finishes of the crown and the screw cap variety. Although the caps shown in those references likewise accommodate variations in dimensional thicknesses, the solution to the problem is quite different from that of the present invention.
U.S. Pat. No. 3,392,862 discloses a triangular bead which is seated under the upper neck bead of the bottle. Such a bead was intended to improve the seal of the cap at the point where the ring contacted the neck, rather than for the purpose of the tension ring which is hereinafter disclosed as a feature of the present invention.
U.S. Pat. No. 3,979,002 disclosed ridges which engaged one of the external beads of the bottle neck, but at a different location than that of the present invention.
U.S. Pat. No. 3,840,137 discloses friction rings which engage the under side of the upper neck bead. However, these do not function in the same manner as the friction bead hereinafter disclosed.
The use of plastic bottle caps having an outward bulge in the skirt immediately below the top disc is well known in the art, as is the feature of forming in the skirt of the cap a horizontal scoreline which extends only partially around the circumference of the cap so that when the scoreline is torn there is a connecting area between the upper part of the cap and the torn portion of the skirt which permits the cap to be reinstalled on a bottle neck during transportation back to the bottling works in order to protect the neck from damage during such transportation. The use of second scorelines which extend down from the horizontal scoreline to the bottom edge of the cap and the provision of tear tabs adjacent the termination of such second scoreline are also well known in this art.